Field of the Invention
The invention relates to a force measuring system for measuring a tensile and/or compressive load applied to a structure, in which the structure is assigned a first force measuring sensor and a second force measuring sensor. The present invention also relates to a method for measuring a tensile and/or compressive load of a structure via the force measuring system, that can include the steps of: measuring of a force applied to the structure by a tensile and/or compressive load using the first force measuring sensor while receiving a first measuring signal; measuring of a force using a second force measuring sensor while receiving a second measuring signal; and evaluation of the first and the second measuring signal
Description of the Background Art
A structure, which can also be referred to as a “measurement structure,” can be used for example as a separate measuring element in load-stressed equipment and machinery or as a component of such equipment and machinery, such as, for example, a crane. Conventional measurement structures are bending beams, axles, bolts, measuring tabs, hooks, carriers, support struts or hydraulic cylinders. These can be subject to a very high mechanical stress, for example tensile, compressive, bending, shear or torsional stress.
For measuring and evaluating a mechanical stress of components it is known to use a force measuring system having one or more force measuring sensors which capture the forces occurring on the measurement structure. Force measurement can be based on various measuring principles, for example, be measured by virtue of force measurement or strain measurement. The force measuring sensor delivers an electrical measurement signal which is evaluated to determine the current force and the tensile and/or compressive load.
The strength of the measurement signal depends on the force measuring sensor used. Its measuring range is designed for a maximum of the expected stress and is also called a “nominal load range”.
In order to obtain a more reliable measurement signal it is known to provide a force measuring system having multiple force measuring sensors. Such a force measuring system is described in DD 243 985 B5, from which a force measuring sensor is also known. It has multiple force sensors in the form of strain gauges, which are disposed relative to the measurement structure in such a way, that a measurement signal is obtained which is optimized in respect of the signal strength.
If forces are to be measured over a large measurement range, the known force measuring sensors display a certain measuring inaccuracy since the measuring accuracy of a sensor does not only depend on its design, but also on the size of its nominal measuring range. In principle, due to the resolution of all force measurement configurations and load cells, it is metrologically given that the measuring accuracy in each lower load measuring range is lower than in the upper load measuring range.